AB0555 SYMPTOMATIC NON-SEROSITIC LUNG INVOLVEMENT IN A MONOCENTRIC COHORT OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS (SLE): A REAL-LIFE EXPERIENCE
Authors: D. Schilirò, E. Elefante, C. Stagnaro, V. Signorini, D. Zucchi, F. Trentin, G. La Rocca, L. Carli, F. Ferro, C. Tani, M. Mosca
Journal: Annals of the Rheumatic Diseases (2022)

Background A growing interest has been addressed to the study of lung involvement in systemic autoimmune diseases. Non-serositic pulmonary manifestations have also been described in SLE. However, little is known about their exact prevalence, clinical features and outcomes. Objectives To describe the prevalence, clinical and immunological characteristics of symptomatic non-serositic lung involvement in a monocentric cohort of SLE patients. Methods This observational, retrospective study included patients with SLE, regularly followed at the Rheumatology Unit of Pisa, that presented a clinically relevant non-serositic pulmonary involvement during their disease history. Patients with lung manifestations related to other causes (e.g. infections, emphysema, Chronic Obstructive Lung Disease, bronchial asthma etc.) were excluded. The following data were collected from clinical charts: demographics, smoke exposure, comorbidities, respiratory symptoms, disease duration and disease activity (SELENA-SLEDAI) at the onset of lung involvement, immunological profile, treatment, CT and spirometry parameters. Results Over 450 SLE patients in regular follow-up, we found 11 female patients with a history of clinically relevant non-serositic lung involvement: 7 interstitial lung disease (ILD), 2 acute lupic pneumonitis (ALP), 1 diffuse alveolar hemorrhage (DAH) and 1 shrinking lung syndrome. 45.4% of patients had a history of smoke exposure and had stopped smoking on average 9 years before the onset of lung manifestations. For the 2 patients with ALP, this was the first manifestation of SLE. Among the other 9 patients, lung involvement was diagnosed after a mean disease duration of 14 ± 15 years. At the diagnosis of pulmonary involvement, 10/11 patients presented respiratory symptoms and an overall active disease, with a median SLEDAI of 9 (IQR 6-13). Clinical characteristics are summarized in Table 1. All patients were hospitalized and 2 of them (1 ALP and 1 DAH) were admitted in intensive care unit. Table 1. Clinical characteristics at the diagnosis of lung involvement Systemic Active skin manifestations 36% Arthritis 36% Fever 36% Leukopenia 36% Hypocomplementemia 91% Anti-dsDNA positivity 36% Respiratory Dyspnea 54% Exertional dyspnea 18% Cough 45% Acute respiratory failure 27% As for the immunologic profile, SSA/Ro60 were positive in 72% of patients and SSA/Ro52, SSB, U1-RNP in 36%; 36% had Sjogren Syndrome (SS) in overlap. Spirometry was available for 6/11 patients: a restrictive pattern and a moderate/severe reduction of diffusing capacity of the lung for carbon monoxide was found in 5 patients. In the ILD subgroup, the most prevalent CT pattern was the Non-specific interstitial pneumonia (NSIP) (5/7). 2 patients presented a Bronchiolitis obliterans/organizing pneumonia (BOOP) pattern. Lung involvement was the driving manifestation in the treatment choice for 6/11 patients: 1 DAH, 2 ALP, 1 Shrinking lung and 2 ILD. All received pulse steroids and in 3 cases (2 ILD and 1 DAH) cyclophosphamide was added for the induction treatment; the patient with Shrinking lung had an overlap SS and was treated with Rituximab. At last visit (mean follow-up of 8 ± 8.7 years since lung disease onset), 7/11 patients presented no respiratory symptoms and a complete resolution of CT alterations. 3/11 presented a residual exertional dyspnea and mild spirometry alterations. No patients developed respiratory insufficiency; only 1 patient died for cardiovascular complications. Conclusion In our large cohort of SLE patients, non-serositic lung involvement seems to be overall rare; the most frequent type of lung manifestation is ILD which appears to be associated with anti-SSA/SSB and anti-U1RNP positivity. The low prevalence of lung involvement (2.4%) in our cohort could be due to the presence of patients with a subclinical involvement. Further studies are needed to assess the real prevalence of subclinical lung manifestations in SLE and to identify the clinical phenotype of patients more prone to develop pulmonary disease. Disclosure of Interests Davide Schilirò: None declared, Elena Elefante: None declared, Chiara Stagnaro: None declared, Viola Signorini: None declared, Dina Zucchi: None declared, Francesca Trentin: None declared, Gaetano La Rocca: None declared, Linda Carli: None declared, Francesco Ferro: None declared, Chiara Tani: None declared, Marta Mosca Speakers bureau: advisor LILLY, ASTRA ZENECA, GSK, Consultant of: advisor LILLY, ASTRA ZENECA, GSK